Squashed 'waflib/' changes from e7a29b6b..27a69a76
Squashed 'waflib/' changes from e7a29b6b..27a69a76

27a69a76 Add option to filter tests by regular expression
ac29b74a Fix configuring with root prefix
6134be69 Print test coverage summary
6d7dd590 Don't attempt to clear coverage when coverage is disabled
cddbcb57 Pass file comparison test if difflib finds no changes
6e4e92b0 Seek to end before checking the size of stderr output

git-subtree-dir: waflib
git-subtree-split: 27a69a76d1f625ad86b60b5dbd12368bc25cae25

drobilla/serd,drobilla/serd